Data Administration and Analysis (DAA) Core support will be provided in all projects of this grant. Core personnel have worked, and will continue to work, closely with project leaders for assuring that each project receives state-of-the-art statistical and data-management support. The specific aims of the DAA Core are: 1.1. To provide study design and review all laboratory, animal and clinical studies, including feasibility assessment, power analysis and sample size estimation. To collaborate in project data analysis, interpretation of results, and the writing of final study reports and manuscripts. 1.2. To provide relational database design, data entry, data tracking, forms, queries, and reports, and to maintain computer databases for information storage and retrieval for all projects. 1.3. To apply methods of longitudinal, survival data and nested-case control design analysis to the cohort of children who will be studied in Project 1. 1.4. To develop dendograms of the genetic relationship among the respiratory syncytial virus (RSV) strains that affect our study subjects in Project 2, and to model and assess the association between RSV genotype and bronchiolitis severity. 1.5. To use repeated measures analysis of variance to assess the effects of interleukin (IL)-17A and other cytokines on airway responsiveness in the in vivo murine model described in Project 3. Similar methods will be used to analyze data from the other specific aims of this project. 1.6. To work with the Clinical and Biospecimen Core to ensure that this core has excellent data management support and to ensure that the needed specimens are collected from the correct patients at the right time. 1.7. To develop and evaluate statistical methods for experimental design and data analysis.